//圆半径
var p=Math.PI;
console.log(p);
var p2=prompt("圆半径");
document.querySelector("#a").value=p2;


//圆周长
var p3=p2*p;
var p4=p3*2;
console.log(p3);
console.log(p4);
document.querySelector("#b").value=p4;

//圆面积
var p6=p2*p2;
var p7=p6*p;
console.log(p6);
console.log(p7);
document.querySelector("#c").value=p7;

